Term
Staph aureus
(ID characteristics & Diseases) |
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Definition
- G POSITIVE, Aerobic, Coagulase POSITIVE
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Can cause: meningitis, necrotizing pneumonia, Skin/soft tissue infections, osteomyelitis, endocarditis, Toxic Shock Syndrome (caused by superantigen)
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Term
Panton-Valentine Leukocidin
Staph aureus Virulence Factor |
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Definition
-WBC lysis causing massive tissue necrosis
-<5% of all S. aureus strains
-Necrotizing & SSTI (CA-MRSA) |
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Term
Hemolysins
S. aureus Virulence Factor |
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Definition
| Causes lysis of erythrocytes |
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Term
Toxin Production
S. aureus Virulence Factor |
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Definition
-Heat stable
-Cause of food poisoning
-Cause of Staphylococcal Scalded Skin Syndrome |
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Term
| How do PCNs work against MSSA? |
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Definition
| Inhibition of penicillin binding proteins from synthesizing peptidoglycan chain and cross linking it w/ AAs; results in cell death |
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Term
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Definition
| -mecA gene codes for PBP2A -Beta lactams have MUCH LOWER affinity for PBP2A |
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Term
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Definition
Anti-Staph PCNs
-Faster action than Vanc
Examples:Methicillin, Nafcillin, Oxacillin, Dicloxacillin |
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Term
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Definition
Cephalosporins
-MSSA produces penicillinase NOT beta-lactamase |
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Term
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Definition
Beta-Lactam + Beta-Lactamase Inhibitor
-Amoxicillin + Clavulanic acid (Augmentin)
-Piperacillin + Tazobactam (Zosyn) |
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Term
| Treatment of MRSA (Severe infections) |
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Definition
Vancomycin is DRUG OF CHOICE
(unless MIC is >2)
--use Daptomycin, Linezolid, Tigecycline |
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Term
| Treatment of MRSA (LESS severe infections) |
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Definition
| -Bactrim, Clindamycin, Minocycline, Doxycycline |
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Term
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Definition
G POSITIVE, Coagulase NEGATIVE
-Common skin flora (contaminate on blood cultures)
-Biofilm production
(colonize & infect catheters/foreign devices)
-Treatment same as MRSA (80%) or MSSA |
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Term
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Definition
G POSITIVE, Coagulase NEGATIVE
Cause of UTIs
(increased incidence in summer/fall) |
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Term
Strep pyogenes
(ID characteristics & Diseases) |
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Definition
G POSITIVE, Beta hemolysis
Can cause:
Strep pharyngitis (acute rheumatic fever)
SSTIs(2nd leading cause)
Necrotizing Fascitis |
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Term
| Treatment of Strep pyogenes |
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Definition
Necrotizing fascitis & pharyngitis
PCN is DRUG OF CHOICE
SSTI
txt difficult w/o culture |
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Term
Strep pneumoniae
(ID characteristics & Diseases) |
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Definition
G POSITIVE, Alpha hemolytic
Can cause:
Morbidity/mortality (common)
meningitis (CA)
pneumonia (CA)
bacteremia
otitis media
sinusitis |
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Term
| Treatment of Strep pneumoniae |
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Definition
-PCN if susceptible (~60%)
-Cephalosporins (4th or 3rd gen (90%)>2nd gen)
(NOT Ceftazidime)
-Quinolones (>90%) (NOT Cipro)
-Vanc (100%) |
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Term
Treatment of Strep pneumoniae
(less severe) |
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Definition
| Macrolides > Tetracyclines > Bactrim |
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Term
| Strep pneumoniae Resistance |
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Definition
PCN: changing PBP
Macrolide: altering ribosome |
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Term
Enterococcus
-E. faecalis
-E.faecium |
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Definition
G POSITIVE, NO exotoxins, NO superantigens
-Adhere well to heart valves & renal epithelium |
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Term
| Enterococcus can cause.... |
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Definition
-UTIs, endocarditis, bacteremia, intra-abdominal infections
-THIRD LEADING CAUSE of nosocomial infections |
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Term
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Definition
-Faecium MORE resistant than facalis
-NO CEPHALOSPORINS WILL WORK!
-PCN: low affinity to PBP5
-AGs: HIGH resistance
-Vanc: Changes D-Ala to D-Lac |
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Term
| Enterococcus UTI Treatment |
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Definition
-Ampicillin or Amoxicillin DRUGS OF CHOICE
-Macrobid, Quinolones |
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Term
| Enterococcus Uncomplicated Bacteremia Treatment |
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Definition
-Amp or Vanc +/- Gentamicin
-CONTROVERSIAL |
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Term
| Enterococcus Complicated Bacteremia Treatment |
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Definition
| -Amp or Vanc +/- Gent or Streptomycin |
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Term
| Vanc Resistant Enterococcus Treatment |
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Definition
-Linezolid is DRUG OF CHOICE (faecium AND facalis)
-2nd line: Quinupristin/Dalfopristin (faecium ONLY) |
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Term
Clostridium
-ANaerobic, G POSITIVE, spore forming |
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Definition
-Dificile: toxin production, diarrhea
-Tetani: toxin production, lockjaw
-Perfringens: toxin production, gas gangrene
-Botulinum: toxin production, flaccid paralysis |
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Term
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Definition
G POSITIVE, Aerobic
Cause of MENINGITIS in children, elderly, immunocompromised patients |
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Term
| Treatment of Listeria monocytogenes |
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Definition
-Ampicillin IV 2g q4h DRUG OF CHOICE
-Bactrim IV--2nd LINE |
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Term
| Corynebacterium diptheriae |
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Definition
G POSITIVE, Aerobic, bacilli
-Colonizes respiratory mucosa
-Potent exotoxin (affects heart, kidneys, CNS)
-Prevention: DPT vaccine
-Treatment: PCN or Erythromycin + Antitoxin (DAT) |
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